Questions and answers: design of surface excavations 325tion angle, but the volume requirements are also much more anisotropic.
This gives greater scope for the designers of the excavation to minimize
the volume of additional (probably wasted) excavation, by preferentially
selecting those dip directions (i.e. 045" and 225") for the excavation faces.
165 180 195030 -L 1 330
015 000 345418.6 Add toppling due to interlayer slip to the analysis of 418.3.A18.6 We use the hemispherical projection plot of fracture normals for
flexural toppling, with a simplified overlay as we are only analysing the
stability of the rock mass when the friction angle is 30". This overlay
is shown below, with the radial scale calibrated directly in the required
Dip direction of slope
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